<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8" />
		<title>姓名案例_计算属性实现</title>
		<!-- 引入Vue -->
		<script type="text/javascript" src="./js/vue.js"></script>
	</head>
	<body>
		<div id="root">
			商品：<input type="text" v-model="goods"> <br/><br/>
			数量：<input type="text" v-model="num"> <br/><br/>
			价格：<input type="text" v-model="price"> <br/><br/>
			<button @click="addinfo">添加到购物车</button><br/>
			<ul>
				<li v-for="c in car">{{c.goods}}的数量是{{c.num}},单价是{{c.price}},小计:{{c.total}}</li>
				<li>总计:总数----{{totalCount}} 总价----{{totPrice}}</li>
			</ul>
		</div>
	</body>

	<script type="text/javascript">
		Vue.config.productionTip = false //阻止 vue 在启动时生成生产提示。

		const vm = new Vue({
			el:'#root',
			data:{
				goods:'',
				num:'',
				price:'',
				car:[
					{goods:'牙刷',num:'5',price:'10',total:'50'},
					{goods:'牙膏',num:'2',price:'20',total:'40'},
					{goods:'镜子',num:'3',price:'30',total:'90'}
				]
			},
			methods: {
				addinfo(){
					const carObj={goods:this.goods,num:this.num,price:this.price,total:this.num*this.price}
					this.car.push(carObj)
					this.goods=''
					this.num=''
					this.price=''
				}
			},
			computed:{
				totalCount(){
					let totalCount=0;
					for (let i = 0; i < this.car.length; i++) {
						totalCount += Number(this.car[i].num);
					}
					return totalCount
				},
				totPrice(){
					let totalPrice=0;
					for (let i = 0; i < this.car.length; i++) {
						totalPrice += Number(this.car[i].total);
					}
					return totalPrice
				}
			}
		})
	</script>
</html>